The invention can be applied advantageously for the production of electronic smart cards.
These cards are produced by a manufacturing method in which an electronic module, mainly formed of a semi-conductive chip disposed on a support fitted with electric contacts, is placed in a cavity arranged on the rear surface of a card body and fixed with a glue, such as a cyanoacrylate-based glue. The cards produced are generally stacked so that the rear surface of one of them is in contact with the rear surface of another.
However, a certain number of cards are altered when they are arranged in this way immediately after the operation for gluing the electronic module in the cavity of the card body. The alteration observed occurs on a portion of the front surface of each card placed against the rear surface bearing the electronic module of the adjacent card and, depending on the case, affects the transparent protective varnish of the card body, the transparent protective plastic film or the actual printed ink.
This alteration is supposed to result from degassing of the glue used and may extend for several days. This may occur without causing any ill effects when it concerns cards without any style of writing on the other side. On the other hand, the alteration is unacceptable when it concerns cards bearing on each of their surfaces a customized decoration conferring said cards with an improved aesthetic increment value.
The aim of the arrangement of cards via simple stacking is to facilitate a subsequent operation, such as handling, storage, shipment or an additional processing. With users in particular, the cards may undergo a customization operation, such as the marking or gluing of magnetic tracks. It is then necessary for the cards to be delivered in a regrouped form with one being placed against the other as they need to be submitted like this for processing.
One solution on altering of the cards, which would consist of changing either the varnish or protective film or the glue, is not desirable. In fact, the actual choice of each of these constituents already results from a best possible compromise concerning their respective properties and advantages: the glue as regards in particular its effectiveness, the varnish or protective film as regards a number of their properties, especially its capacity for electrostatic dispersion, hooking of the magnetic track and resistance to scratches.
A further solution able to avoid the deterioration of the cards could consist of deferring their storage for a certain period of time or storing them temporarily in a charger in which the cards would be kept separate from one another. However, these solutions are unsatisfactory as the period of degassing is relatively long and may last several days. In addition, they are incompatible with the delivery periods requiring large storage volumes and can result in a production stoppage.
Another drawback of resorting to using the charger is of impeding subsequent operations to the extent that the cards needed to be handled one by one so as to combine them for a serial processing. This subsequent processing may be carried out either in the plant or at the premises of the user. It includes all sorts of operations, such as packing into individual bags or user customization.
Also, the technical problem to be resolved by the present invention is to put forward a method for storing a plurality of electronic smart cards each comprising firstly a card body having one rear surface and one front surface, said method being able to avoid the drawbacks mentioned above by preventing the alteration of the smart cards in the production process and by facilitating subsequent operations.